A dominant mutation with variable penetrance and expressivity induced by diethyl sulfate in peanuts, Arachis hypogaea L.

Seeds of peanuts, A. hypogaea L. were soaked in a saturated solution of diethyl sulfate. A monogenic dominant mutation with recessive lethal effects was discovered in the M₁ and studied till the M₇. Heterozygous plants are either extremely dwarfed, diminutive and leafletless or intermediate between diminutive and normal, or mixed, i.e., they start as diminutive and then produce some perfectly normal branches. The phenotypic change yielding the mixed plants is not accompanied by a genotypic change, thus no paramutation is involved. The mutation affects the hormone balance of the plants; diminutive plants produce normal growth when sprayed with gibberellic acid. The similarities and differences between the behavior of this mutation and phase change in higher plants, unstable loci and paramutation are discussed.